Goodnight Demon Slayer
by PrussianTails
Summary: Side shot from Wammy High (don't have to read WH for this) in which we see when B created his lullaby for Matt when he first took him in. Rated T for language.


A/N: This is a side-shot to my fan fiction Wammy High. This is basically a scene from Matt's childhood and when Beyond created his song he uses as a lullaby for him. Of course it's no twinkle twinkle little star. Lol. You don't have to read Wammy High to be able to read this. I just had a few people actually wanting it and, hell.. I wanted to do it pretty badly. So, for those of you who don't know, in WH, Beyond is Matt's legal guardian. He rescued him from an Orphanage they were both in. Of course, Beyond is almost 10 years his senior, but he swore when he turned 18, he'd save his friend from the house that was so terrible to them.

 **Goodnight Demon Slayer**

It was dark. Way too dark. In the corner, sitting up against the wall on his bed sat a little boy at the age of 12. His thin arms were wound tightly around his knees, holding them together as tight as possible. His shoulders shook with quiet sobs, his bottom lip bleeding as he bit to hard in his attempt to not make any noise. Outside the moon was high and shone in through his window. At first, he was grateful there were no bars to hold him prisoner. But now.. He wondered what would stop someone from getting _in_.

A bright streak of lightning lit up the sky outside, flashing shadows on his bedroom walls. Suddenly, rain was pounding on his window and a crack of thunder rumbled too close. The boy shrieked and dove under the covers, tugging at his bright red locks now as he covered his eyes with his goggles, his most prized possession.

The sound of hurried footsteps seemed even louder and ominous than the storm raging outside, and he held his breath, realizing his mistake at crying out. Another quiet sob broke through him, and he gasped as his bedroom door opened with a slight creak and thud on the wall.

"Matty?!" A voice called, sounding every bit the concerned parent. But the red head flinched and buried his face into his shaking knees. He could here the other panting as he got closer, slightly winded from his dash into his room. His blanket was pulled from his head and he cowered away, attempting to shrink his body into the wall. "Oh, Matty!" despair sounded in the words and the man sank to the edge of the bed, tentatively reaching a hand out to grip his own tightly, rubbing circles on the back of it.

"No!" The boy cried, tugging at his limb as tears stung his eyes.

"Matty, look at me!" The other called, refusing to let go. The red head shook his head fiercely. He didn't want to look at him! It was easier to ignore when he kept his eyes shut. "Look at me, Mails!" He demanded. Green eyes shot open at the name, widened in shock and fear as they landed on the pair of crimson orbs that were watching him.

"Beyond!" He cried, flinging himself into the older mans arms, a loud cry escaping him as he slammed into the larger chest. Tears fell freely now, and he didn't hold back the cries that came from deep within his chest. Beyond's air was slightly cut off from such a tight grip around his neck, and his t-shirt was already starting to soak through on his left shoulder, but he couldn't care less. His own arms firmly held the young boy to himself, a hand moving through his messy red locks as he made shushing noises.

"It's ok, Matty. It's ok. I'm here. You're with me in my house. You never have to go back there! They can't come here!" He promised over and over again. The boy cried out again, arms twitching even tighter as he attempted to impossibly burrow even closer.

Beyond wasn't sure how long they sat there, and he didn't care. All he knew was that right now, Matt needed him. He cursed himself for not being able to save them sooner. When he was with them, he was able to protect them from the cruelty in the house, but when he turned 18, he was cast out. Of course, he immediately filed to take Matt and Near with him. L had set him up with a great job that he started on his 18th birthday. Of course, the system required him, as a single man, to prove himself worthy of the adoption. At the ripe age of 18, they were weary of allowing him to do so. Now he was 20. It had taken him almost two years to get them, and even then a big part of it had been because of the mass investigations that began on houses like it. In that time, Matt had taken it upon himself to protect his friend, Near, who was smaller and weaker. Just like Beyond had protected him. Except Matt couldn't completely fight against them like Beyond could, and he had suffered for it. Beyond had been too late to save him from so many things, and the thought made him murderous.

Soon, Beyond heard sniffling and Matt was pulling away to wipe at his eyes to apologize, "I'm sorry. I don't know what is wrong with me! I'm being a baby!" The red head looked away in shame, still rubbing his face with his striped sleeves. Beyond sighed and reached out, hugging him once more.

"Shh, don't be sorry. It's ok. I'm here for you, now." He said, swallowing past his own lump in his throat. Matt shook his head and pushed back again.

"No really. I'm not a baby, I shouldn't be crying like one." He laughed out, pulling his goggles more securely over his face as he looked up at his guardian. Beyond smiled weakly at him.

"Hey, next door I was checking for monsters under the bed, I think you're ok." He joked, but Matt's eyebrows shot up as his eyes grew wide and he looked down frantically. "Matty, it's ok! Nothing can even be under there." He hurried to sooth. The red head flushed in embarrassment. Of course there wasn't. Beyond had done his best to set the house up for them, but kept it relatively simple with futons and basic furniture. He had planned to let them decorate how they wanted to.

"I.. Knew that.." Matt said quietly, a small laugh escaping him.

"He, it's ok. You've.. been through a lot." He trailed off, unsure what to say or how to comfort him. Matt rubbed his arm meekly and refused to look at him.

"Yeah.." He whispered, biting his already scabbed lip.

"Fucking hell.." He sighed in exasperation. "I'm not good at this, I'm sorry. I just don't know what to do. None of it should have every happened to you, and it's my fault it did. I should've just _taken_ you guys with me." He groaned, head tilted back as he stared at the ceiling. He was brought back to the moment and looked down to meet uncovered green eyes when a small hand touched his own. The boy was smiling weakly at him.

"You're here _now_." The boy whispered, pulling forth a small smile in return from Beyond.

"Yeah, I am. Just.. Please, tell me if you know of anything I can do to help you." He pled, eyes full of concern. Matt seemed to think for a moment before lighting up.

"Sing to me?" He questioned with more flushed cheeks. Music had always calmed him down, and him and Beyond used to make up their own songs in the orphanage all the time. He looked up to the other boy growing up, and still wanted nothing more than to be just like him. He had even began to sing, though he wasn't nearly as good as Beyond.

"Sure." He smiled and thought for a moment, getting an idea before he began.

 **There's a monster that lives 'neath your bed**

 **Oh for crying out loud it's a futon on the floor**

 **He must be flat as a board**

 **There's a creature that lurks behind the door**

 **Though I've checked there 15 times**

 **When I leave then he arrives**

 **Every Night**

Matt giggled to himself as Beyond acted exasperated, though he knew he would gladly flip every futon in the house for himself and Near if they asked. Crimson eyes sparkled as he he leaned towards him, a smirk playing at his lips.

 **Tell the monster that lives 'neath your bed**

 **To go somewhere else instead**

 **Or you'll kick him in the head**

 **Tell the creature that lurks behind the door**

 **If he knows what's good he won't come here no more**

 **Cause you'll kick in his butt at the count of four**

Beyond was suddenly hugging him as he laughed a little louder.

 **Goodnight demon slayer, goodnight**

 **Now it's time to close your tired eyes**

 **There's devils to slay and dragons to ride**

 **If they see you coming, hell they better hide**

 **Goodnight, goodnight, goodnight**

 **Goodnight my little slayer goodnight.**

Matt found himself alone on his bed as the raven haired man stood up before he reached down and pulled him to his feet as well. As he continued to sing, he pulled Matt with him, faking like he was fighting some invisible monsters, dueling with swords, and dodging fire when lightning shone through.

 **Tell the monster that eats children that you taste bad**

 **And you're sure you'd be the worst he's ever had**

 **If he eats you, don't you fret, just cut him open with an axe**

 **Don't regret it, he deserved it, he's a cad**

 **Tell the harpies that land on your bed post**

 **That at the count of five, you'll roast them alive**

 **Tell the devil it's time you gave him his dues**

 **He should go back to hell, he should shake in his shoes**

 **Cause the mightiest, scariest, creature is you**

He sang he last line, eyes locked on Matts own, making his point as he tapped his small chest with a finger. Matt couldn't help but smile with pride as warmth filled him before he found himself in another hug. Beyond carried him back to his bed as he continued to sing to him.

 **Goodnight demon slayer, goodnight**

 **Now it's time to close your tired eyes**

 **There's devils to slay and dragons to ride**

 **If they see you coming, hell they better hide**

 **Goodnight, goodnight, goodnight**

 **Goodnight my little slayer goodnight.**

Matt laid down, clutching his pillow to his body. Lightning continued to flash and thunder seemed to punctuate Beyonds voice. But now, the shadows seemed less scary and the sound of rain comforting. Beyond raised his blanket up over him and tucked it around his body. He smiled gently, a hint of sadness in his eyes as he continued.

 **I won't tell you, there's nothing 'neath your bed**

 **I won't sell you that it's all in your head**

 **This world of ours is not as it seems**

 **The monsters are real, but they're not in you dreams**

 **Learn what you can from the beasts you defeat,**

 **you'll need it for some of the people you'll meet**

Matt's eyes stung once again as he listened and he instinctively reached out a hand to clutch Beyonds bigger one. He pulled it to him and buried his face in their joined hands, but managed to keep the small smile that played on his lips. If Beyond could believe in him, then he could believe in himself.

 **Goodnight demon slayer, goodnight**

 **Now it's time to close your tired eyes**

 **There's devils to slay and dragons to ride**

 **If they see you coming, hell they better hide**

 **Goodnight, goodnight, goodnight**

 **Goodnight my little slayer goodnight.**

 **Goodnight, goodnight, goodnight**

 **Goodnight**

Beyond's fingers slid through crimson locks, his eyes still sad and gentle as he looked down on his ward. Matt had fallen asleep finally, and he felt his heart clenched at the peaceful look on his face. How long had it been since he had seen his features so relaxed? Tears blurred his own vision as he thought about everything he would probably never know this boy went through. He knew tomorrow they would probably go through this again. Hell, it could be months before things started to even remotely be normal in their house. But he couldn't bring himself to truly care. He would gladly stay awake to help guard these two boys from the demons of the night if they needed him. He would sing every night, and hold himself together in front of them. He would be their rock and help them learn to trust again. That it was ok to love and make sure they knew that they were loved at least by him.

He knew he must seem crazy to people on the outside looking in. Why would a bachelor who just entered adulthood want to adopt two pre-teens? Even L had questioned him until he had told him the things that went on in that house. L had been shocked, to say the least and had actually began multiple investigations into the system and as many homes like it as he could. Which was a lot considering he was one of he most sought after detectives in the world. Beyond, of course, would do all he could to help. L had even began to talk about funding his own orphanage, but he wasn't sure if that was going to happen, nor did he know if it would be soon.

He sighed as he pulled away from the sleeping child before him, leaning down to leave a light kiss upon his temple, "You kick those demon asses in your dreams, Matty. And out here, I'll make sure to help you stand strong against these ones as well. I promise." He whispered. The boys lips quirked in a smile as he continued to sleep on, and he straightened once more before heading out the door. He knew sleep wouldn't exactly come to his insomniac mind and body, but he would be keeping his promise as he worked on his case he was helping L build. And of course, he'd be here as soon as he was called for.

(- _end_ -)

A/N: *hands out tissues* I know I didn't elaborate exactly what Matt went through at the orphanage, but that's because that will be in Wammy High eventually. So.. Thoughts? I absolutely loooooove their relationship in this arc. Especially when Matt grows up and is a teenage man whore bantering with his adoptive father. Who knew Beyond would be so soft and squishy inside? Haha. Anyways.. I hope you enjoyed it.

Song Used: "Goodnight Demon Slayer" by Voltaire.


End file.
